What the last poster meant is that if you locate the AppCompatFlags\Layers key in the correct hive you can remove the key that is stored for the particular devenv.exe.

However, I just learned that it is not always saved in HKCU or HKLM I just found mine buried in the HKU for my domain user. Scan your whole registry for AppCompatFlags and keep looking in the Layers subkey, if you are diligent you will find the one key.